Gen-Z: “more bandwidth than PCI-Express or DDR4 slots in a much smaller form factor”.............................
"A native Gen-Z switch would be on the order of 3X to 13X faster, and with maybe 2.5X to 8X the bandwidth."
Innovators and entrepreneurs with new materials and techniques. Here, history does repeat. Over and over and over. Ever faster and faster and faster.
Future Interconnects: Gen-Z Stitches A Memory Fabric
It is difficult not to be impatient for the technologies of the future, which is one reason that this publication is called The Next Platform. But those who are waiting for the Gen-Z consortium to deliver a memory fabric that will break the hegemony of the CPU in controlling access to memory and to deepen the memory hierarchy while at the same time flattening memory addressability are going to have to wait a little longer.
About a year longer, in fact, which is a bit further away than the founders of the Gen-Z consortium were hoping when they launched their idea for a memory fabric back in October 2016. These things take time, particularly any standard being raised by dozens of vendors with their own interests and ideas.
It has been almost a year now since Gen-Z launched, and the consortium is growing and the specifications are being cooked up by the techies. The core Gen-Z spec was published in December 2016 and updated in July to a 0.9 level; it is expected to be at the 1.0 level before the end of the year. The related The PHY spec is at about a 0.5 release level, and it should be at the 1.0 release level by the end of the year. And interestingly, the Gen-Z folks are showing off a new connector spec developed in conjunction with Tyco Electronics that uses 112 GT/sec signaling that delivers more bandwidth than PCI-Express or DDR4 slots in a much smaller form factor. (More on this in a second.)
We think there is a very good chance that InfiniBand and Ethernet switches will have circuits added to carry the Gen-Z protocol. The important thing to remember is that the PCI-Express and Ethernet physical layers have been honed over time, and will continue to evolve, and Gen-Z will ride on top of this as well as very likely get its own native hardware with its own specific benefits, such as super-low latency. The best 100 Gb/sec InfiniBand switches (including Intel’s Omni-Path as well as Mellanox Technologies’ Switch-IB) have around 100 nanoseconds of port-to-port latency, and the average 100 Gb/sec Ethernet switch is in the range of 300 nanoseconds to 400 nanoseconds. A native Gen-Z switch would be on the order of 3X to 13X faster, and with maybe 2.5X to 8X the bandwidth.
This new Gen-Z connector is also an important innovation.